Bottle inspecting device



Patented Oct. 14, 1941 n. im

BOTTLE INSPECTING DEVICE Lawrence T. Sachtleben, Camden, N. J., assignor to Radio Corporation of America, a corporal I tioniof Delaware Application August 18, 1937, Serial No. 159,643

4 Claims.

= filed Marchal, 1937, now Patent No. 2,192,580,

` issued March 5, 1940.

, and claimed an apparatus for inspecting the liquid contents of bottles and, more particularly, bottles having a portion of their surface fluted, wherein the bottle was rotated to bring the contents into rotation and then the bottle was stopped. An appropriate optical system focused y one or more sharp lines of light adjacent the interior surface of the bottle and any extraneous matter in the contents would interrupt' a por- .l tion of the sharply focused light, thereby pro- Iducing appropriate response from a photocell hich, in turn, passed impulses through an am- -pliiier tuned to the frequency of rotation of the .Y hopttled contents, causing an appropriate indiy I ,f c'. tion or the discarding of the bottle by the appa atus.

y/ The invention of the present application is l y an improvement on that of the said earlier apf plication in that length of the optical system is y decreased, the precision of the optical system is improved and the intensity of the illumination,

particularly at portions of the bottle wh-ere forv eign materials are most likely to occur, is increased.

These improvements are accomplished by improvements in the type and arrangement of the lenses used for focusing the light within the bottle.

' An object of my invention is to provide an illuminating system of improved eiciency.

Another object of my invention is to provide means for directing a beam of light through a bottle with much greater light intensity nearer y the bottom of the bottle than at other portions.

i Other and incidental objects of my invention will be apparent to those skilled in the art from a reading of the following specification and-an inspection of the accompanying drawing in which Figure 1 is an elevation of my improved optical system, and

f; 'Figure 2 is a plan view thereof, partly in section. y

Referring iirst to Fig. 1, an exciter lamp IU is provided havingl a filament II in the form of a single axial helix. The lamp is supported in the usual socket I2 and the electrical filament is maintained in predetermined position by holdand claimed in my application SerialNo. 133,992,

In the said application, thereA was described Y ing the envelope of the lamp I in position by means of a spring-pressed cap I3 cooperating with the rounded upper end of the bulb. A concave spherical reflector, preferably of the backsilvered glass type, I6 is provided, which serves to increase the effective intensity of the illumi- 'nation. Light from the lament II and the reected image thereof produced bythe mirror I4 passes through the cylindrical lens l5 and the diaphragm I 6 toward the object to be illuminated. This cylindrical lens is preferably made `of a crown glass having an index of refraction of 1.517 and is about 1%, inches wide and 21/2 inches long, having vradii on both faces of 1.432 inches. This lens is located with its nearer face at a distance of approximately 1%; inches from the filament II, which is substantially its own focal length. This lens therefore directs a beam of light substantially parallel transversely through the diaphragm I6.

The light from the filament I I .passing through the lens I5 is spread over a considerable vertical angle, but only the light showing within an angle of about 30, i. e., about 15 above and below the horizontal axis of the apparatus, falls upon the bottle Il. An appropriate supporting member I8 is provided consisting of a piece of plane parallel glass, such as plate glass, and to the surface thereof are fastened the lenses I9 and 20. The lens I9, which is a plane cylindrical lens having its axis vertical, serves to -focus th'e light in the belt 2| of the bottle where no iiutes occur, the iiutes themselves serving as lenses to focus the line of light within the bottle in the portions 22 and 23. I

Light focused Within the bottle in the form of a narrow line, either by the iiutes at 22 and 23 or by the lens I9, is interrupted by the passage oi' any-obstructions in the rotating con- 40 tents of the bottle, as above described, andpori respondingly affects the photoelectric device 24, which is connected to an appropriate amplifier and which, in turn, operates an appropriate indicating or other signal responsive means. 4,5--ffThe lens I9 and, likewise, the lens 20 have a width of 3A of an inch and a radius of .646 inch and, like the lens I5, are made of crown glass having an index of refraction of 1.517, these lenses being located at a distance of 21/2 inches from the center of the bottle.

It will be apparent that a considerable portion of the light from the filament II passes through the lens I5 outside of the 30 angle within which it would fall upon the bottle Il. It is highly desirable, since particles of foreign material would normally accumulate near the bottom of the bottle, to have considerably increased illumination at this point. I accordingly provide a pair of lenses 25 and 26, just below the portion of the beam normally striking the bottle, in order to direct the light which would otherwise miss the bottle, into the bottom portion thereof. These lenses each have a length measured horizontally of 11/2 inches and a height of 11/4. inches, the radius of the curvature thereof being 2.63 inches. and the center line is spaced at a distanceof 3.7 inches from the iilament, as measured along their optical axes. These lenses retract the light passing through the lower'portion of the lens I5 upwardly, causing it to strike the lens 20 which. in turn, converges it into the lower portion of the bottle IT. 'This arrangement increases the il lumination in the lower portion of the bottle by at least three or four times as compared with the illumination at the upper parts of the bottle and correspondingly increases the sensitivity of the aatasai apparatus in detecting any foreign materials which might be in the lowerportipn of the bottle. .Y

The focal length of the lenses and 28 is so chosen that an image of the lament I I is formed within the nearer surface of the object with a vertical magnification of about two to one, the length of the axial coil illament II being about of an inch.

e if) If it is desired to also use the light passing through the upper portion of the lens I5, a`pair ssresrnendleillr'fhane of ihe'pap iFig `l may be provided. These mirrors are preferably ...a l//f/ 4....

i'iuview'of their probable exposure to damageof gue glass typesilvered .on theirsuracrsarrthen imay bf'eadmof an appropriate, QQQQQIIQSWL metall The curvature of the mirrors is so chosen that an image of the filament il is produced 4 into predetermined portions of the said object.

v light source, a cylindrical lens adjacent said lens substantially outside ofthe normal path of light from said lamp to said object for directing light from outside of the direct beam passing through the mst 1ens to the said object to predetermined portions of said object.

2. Apparatus of the class described, comprising an incandescent lamp, a cylindrical lens for directing a beam of light from said lamp into an object to be inspected, additional cylindrical lens means arranged transversely of said iirst lens substantially outside oi the normal path of light from said lamp to said object for directing light from outside of the direct beam passing through the iirst lens to the said object to predetermined portions of said object, and cylindrical reflecting means i'or also directing additional light from outside of the direct beam to the said object to predetermined portions of said object.

3. Apparatus of the class described, comprising a light source, means for holding an object to be inspected in predetermined relation to said light source for directing a beam of parallel light from said source to said object, additional cylindrical lens means for focusingolight from said parallel beam to a narrow line within said object," said cylindrical lens means all having their axes in the same plane, and additional cylindrical lens means substantially outside of the normal path of light from said lamp to said object having an axis perpendicular to the said plane for directingadditional light passing through the iirst lens 4. Apparatus of the class described, comprisin a light source, means for holding an object to b 1 inspected in predetermined relation to said ligli source, a cylindrical lens adjacent said liiht source for directing a beam of parallel light from said source to said object, additional cylindrical lens means for focusing light from said parallel 

